This invention relates to a fastener and the method by which it is mounted on a piece of sheet material.
A fastener has previously been mounted on sheet material by cutting away a portion of the sheet material with a center section of the fastener and forcing the sheet material into a recess formed in the fastener. Thus, U.S. Pat. Nos. 3,276,499; 3,337,946 and 3,724,520 disclose fasteners having center sections which are used to cut away a portion of a piece of sheet material. Dies are used to force the sheet material into recesses formed in these known fasteners.
Although known fasteners which are mounted in sheet material have been more or less satisfactory in their operation, difficulty has been encountered in holding these known fasteners against rotation and/or axial movement relative to a piece of sheet material on which they are mounted. Therefore when a cooperating fastening element engages the sheet material mounted fastener, the cooperating element may pull the mounted fastener out of the sheet material and/or may rotate the mounted fastener relative to the sheet material. This is especially true when one of the threaded elements has a locking feature.